import { useState, useRef } from 'react'
import {
  BarChart, Bar, Cell, XAxis, YAxis, Tooltip, LabelList,
  ResponsiveContainer, ReferenceLine,
} from 'recharts'
import { motion } from 'framer-motion'
import { Download } from 'lucide-react'
import { useUsageLimiter } from '../hooks/useUsageLimiter'
import AccessModal from '../components/AccessModal'
import { ReportTemplate } from '../components/ReportTemplate'
import DefinitionOfTerms from '../components/DefinitionOfTerms'

const API_URL = import.meta.env.VITE_API_URL || 'http://localhost:8000'

// ── Types ─────────────────────────────────────────────────────────────────────
interface Ledger {
  intrinsic_performance_value: number
  category: string
  depreciation: number
  baseline_value: number
  external_multiplier: number
  hard_cap: number
}
interface EvalResult {
  ledger: Ledger
  nlp_results: { durability: number; recency: number; agent: number }
  nlp_cached: boolean
  nlp_found?: boolean
  logs: string[]
  shap_data: { feature: string; impact: number }[]
}

// ── Gauge (SVG speedometer) ────────────────────────────────────────────────────
function Gauge({ asking, hardCap }: { asking: number; hardCap: number }) {
  const maxVal = Math.max(asking * 1.25, hardCap * 1.25, 50)
  const cx = 150, cy = 138, r = 108

  const toRad = (deg: number) => (deg * Math.PI) / 180
  const pt = (deg: number) => ({
    x: cx + r * Math.cos(toRad(deg)),
    y: cy + r * Math.sin(toRad(deg)),
  })

  const frac = (v: number) => Math.min(v / maxVal, 1)
  const capDeg  = -180 + frac(hardCap) * 180
  const askDeg  = -180 + frac(asking)  * 180
  const isOver  = asking > hardCap

  const arc = (a1: number, a2: number) => {
    const s = pt(a1), e = pt(a2)
    const large = a2 - a1 > 180 ? 1 : 0
    return `M ${s.x.toFixed(1)} ${s.y.toFixed(1)} A ${r} ${r} 0 ${large} 1 ${e.x.toFixed(1)} ${e.y.toFixed(1)}`
  }

  return (
    <svg viewBox="0 0 300 165" style={{ width:'100%', maxWidth:320 }}>
      {/* Track */}
      <path d={arc(-180,0)} fill="none" stroke="rgba(255,255,255,0.06)" strokeWidth={18} strokeLinecap="round"/>
      {/* Green zone: 0 → cap */}
      <path d={arc(-180, capDeg)} fill="none" stroke="var(--profit-color)" strokeWidth={18} strokeLinecap="round" opacity={0.85}/>
      {/* Red zone: cap → asking (only if over) */}
      {isOver && (
        <path d={arc(capDeg, Math.min(askDeg, 0))} fill="none" stroke="var(--loss-color)" strokeWidth={18} strokeLinecap="round" opacity={0.85}/>
      )}
      {/* Needle */}
      <line x1={cx} y1={cy} x2={pt(askDeg).x} y2={pt(askDeg).y} stroke="white" strokeWidth={2.5} strokeLinecap="round"/>
      <circle cx={cx} cy={cy} r={5} fill="white"/>
      {/* Fair Value label */}
      <text x={pt(capDeg).x + (capDeg < -90 ? -6 : 6)} y={pt(capDeg).y - 6}
        textAnchor={capDeg < -90 ? 'end' : 'start'}
        fill="var(--profit-color)" fontSize={9} fontWeight={600}>
        Fair Value £{hardCap.toFixed(0)}m
      </text>
      {/* Center: asking */}
      <text x={cx} y={cy + 22} textAnchor="middle" fill="white" fontSize={22} fontWeight={800}>
        £{asking.toFixed(0)}m
      </text>
      <text x={cx} y={cy + 40} textAnchor="middle"
        fill={isOver ? 'var(--loss-color)' : 'var(--profit-color)'} fontSize={12} fontWeight={600}>
        {isOver
          ? `▲ £${(asking - hardCap).toFixed(1)}m OVER FAIR VALUE`
          : `✓ Within Fair Value`}
      </text>
      {/* Scale ticks */}
      {[0, 0.25, 0.5, 0.75, 1].map(f => {
        const deg = -180 + f * 180
        const inner = { x: cx + (r-12) * Math.cos(toRad(deg)), y: cy + (r-12) * Math.sin(toRad(deg)) }
        const outer = { x: cx + (r+2)  * Math.cos(toRad(deg)), y: cy + (r+2)  * Math.sin(toRad(deg)) }
        return <line key={f} x1={inner.x} y1={inner.y} x2={outer.x} y2={outer.y} stroke="rgba(255,255,255,0.15)" strokeWidth={1}/>
      })}
    </svg>
  )
}

// ── SHAP Chart ────────────────────────────────────────────────────────────────
function ShapChart({ data }: { data: { feature: string; impact: number }[] }) {
  return (
    <ResponsiveContainer width="100%" height={260}>
      <BarChart data={data} layout="vertical" margin={{ left: 0, right: 24, top: 4, bottom: 4 }}>
        <XAxis type="number" tick={{ fill:'var(--text-2)', fontSize:10 }} axisLine={false} tickLine={false}/>
        <YAxis type="category" dataKey="feature" tick={{ fill:'var(--text-2)', fontSize:11 }} width={140} axisLine={false} tickLine={false}/>
        <Tooltip
          cursor={{ fill:'rgba(255,255,255,0.04)' }}
          contentStyle={{ background:'var(--bg-elevated)', border:'1px solid var(--glass-border-hi)', borderRadius:8, fontSize:12, color:'var(--text-1)' }}
          itemStyle={{ color: 'var(--text-1)' }}
          labelStyle={{ color: 'var(--text-2)', marginBottom: 4 }}
          formatter={(v: number) => [v > 0 ? `+${v.toFixed(3)}` : v.toFixed(3), 'Market Impact']}
        />
        <ReferenceLine x={0} stroke="rgba(255,255,255,0.12)" strokeWidth={1}/>
        <Bar dataKey="impact" radius={3}>
          <LabelList 
            dataKey="impact" 
            position="right" 
            fill="var(--text-1)" 
            fontSize={11} 
            fontWeight={600} 
            formatter={(v: number) => v > 0 ? `+${v.toFixed(2)}` : v.toFixed(2)}
          />
          {data.map((entry, i) => (
            <Cell key={i} fill={entry.impact >= 0 ? 'var(--profit-color)' : 'var(--loss-color)'} fillOpacity={0.85}/>
          ))}
        </Bar>
      </BarChart>
    </ResponsiveContainer>
  )
}

// ── NLP Sentiment Score ───────────────────────────────────────────────────────
function SentimentScore({ label, value, icon, found }: { label: string; value: number; icon: string, found?: boolean }) {
  const pct = Math.round(((value + 1) / 2) * 100)
  const isNeutral = value === 0
  const color = value > 0.1 ? 'var(--profit-color)' : value < -0.1 ? 'var(--loss-color)' : (isNeutral && found ? 'var(--text-3)' : 'var(--accent-blue)')
  
  return (
    <div>
      <div style={{ display:'flex', justifyContent:'space-between', marginBottom:6 }}>
        <span style={{ fontSize:'0.8rem', color:'var(--text-2)', display:'flex', gap:6, alignItems:'center' }}>
          {icon} {label}
        </span>
        <span style={{ fontSize:'0.8rem', fontWeight:700, color }}>
          {isNeutral ? (found ? 'Neutral' : 'No Data') : (value > 0 ? '+' : '') + value.toFixed(2)}
        </span>
      </div>
      <div className="sentiment-bar-track">
        <div className="sentiment-bar-fill" style={{ width:`${pct}%`, background:color }}/>
      </div>
    </div>
  )
}

// ── Custom Loaders ────────────────────────────────────────────────────────────
function AILoader() {
  return (
    <div style={{ display: 'flex', flexDirection: 'column', alignItems: 'center', gap: 20, margin: '40px 0' }}>
      <motion.div
        animate={{ 
          rotate: 360,
          scale: [1, 1.2, 1],
          y: [0, -40, 0]
        }}
        transition={{ 
          rotate: { duration: 1.5, repeat: Infinity, ease: "linear" },
          y: { duration: 0.5, repeat: Infinity, ease: "easeOut", repeatType: "mirror" },
          scale: { duration: 0.5, repeat: Infinity, ease: "easeInOut" }
        }}
        style={{ fontSize: '64px', lineHeight: 1, filter: 'drop-shadow(0 20px 15px rgba(0,0,0,0.6))' }}
      >
        ⚽
      </motion.div>
      <div style={{ textAlign: 'center' }}>
        <motion.div 
          animate={{ opacity: [0.4, 1, 0.4] }}
          transition={{ duration: 1.5, repeat: Infinity, ease: "easeInOut" }}
          style={{ fontSize: '0.9rem', color: '#60a5fa', fontWeight: 800, letterSpacing: '0.2em' }}
        >
          SCOUTING DATA CHANNELS...
        </motion.div>
        <div style={{ fontSize: '0.7rem', color: 'var(--text-3)', marginTop: 4 }}>
          Accessing Premier League Performance Archives
        </div>
      </div>
    </div>
  )
}

function ButtonPulse() {
  return (
    <motion.div
      animate={{ rotate: 360 }}
      transition={{ duration: 1, repeat: Infinity, ease: "linear" }}
      style={{
        fontSize: '14px',
        lineHeight: 1,
        marginRight: 6,
        display: 'inline-block'
      }}
    >
      ⚽
    </motion.div>
  )
}

// ── Main Estimator Page ───────────────────────────────────────────────────────
export default function Estimator() {
  const { isLocked, incrementUsage } = useUsageLimiter()
  const reportRef = useRef<HTMLDivElement>(null)
  const [form, setForm] = useState({
    selected_name: '',
    current_club: '',
    interested_club: '',
    contract_years: 3,
    age: 24,
    injuries_24m: 10,
    asking_price: 45,
    market_value_estimation: 40,
  })
  const [result, setResult]   = useState<EvalResult | null>(null)
  const [loading, setLoading] = useState(false)
  const [error, setError]     = useState<string | null>(null)
  const [showLog, setShowLog] = useState(false)

  const set = (k: string, v: string | number) => setForm(f => ({ ...f, [k]: v }))

  const handleSubmit = async (e?: React.FormEvent) => {
    if (e) e.preventDefault()
    
    // Auto-Format the Player Name so the PDF always looks professional
    let cleanName = form.selected_name.trim()
    // Apply Title Case for unrecognized players (e.g. "john doe" -> "John Doe")
    cleanName = cleanName.replace(/\b\w/g, c => c.toUpperCase())
    
    if (cleanName !== form.selected_name) {
      setForm(prev => ({ ...prev, selected_name: cleanName }))
    }

    if (!cleanName) { setError('Player name is required.'); return }
    if (!incrementUsage()) return;
    
    setLoading(true); setError(null); setResult(null)
    try {
      const res = await fetch(`${API_URL}/api/evaluate`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify(form),
      })
      if (!res.ok) {
        const err = await res.json().catch(() => ({}))
        throw new Error(err.detail || `API error ${res.status}`)
      }
      setResult(await res.json())
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Unknown error — is the API running?')
    } finally {
      setLoading(false)
    }
  }

  const handleDownloadPdf = () => {
    // Temporarily change document title so the native Print/Save dialog
    // automatically uses this as the default PDF file name.
    const originalTitle = document.title
    const safeName = form.selected_name.replace(/\s+/g, '_') || 'Player'
    document.title = `FairValue_Report_${safeName}`
    
    // Rely on native browser print for high-fidelity, copyable vectorized PDFs
    window.print()
    
    // Restore the original title after the print dialog resolves
    setTimeout(() => {
      document.title = originalTitle
    }, 1000)
  }

  const L = result?.ledger

  return (
    <div className="page">
      <div className="no-print">
        {isLocked && <AccessModal />}
        <div className="container">

          {/* Header */}
        <div style={{ marginBottom:36 }}>
          <span className="badge badge-green" style={{ marginBottom:10, display:'inline-flex' }}>AI Valuation Engine</span>
          <h1 style={{ marginBottom:8 }}>Strategic Transfer Estimator</h1>
          <p>Evaluate a transfer ceiling guided by ML valuations and multi-axis NLP intelligence.</p>
        </div>

        <div style={{ display:'grid', gridTemplateColumns:'380px 1fr', gap:24, alignItems:'start' }}>

          {/* ── Left: Form ────────────────────────────────────────────────── */}
          <div style={{ display:'flex', flexDirection:'column', gap:16 }}>

            <div className="glass-flat" style={{ padding:24 }}>
              <h3 style={{ marginBottom:20, color:'var(--text-1)' }}>Player Profile</h3>

              <div style={{ display:'flex', flexDirection:'column', gap:14 }}>
                <div className="input-group">
                  <label className="field-label">Player Name *</label>
                  <input className="input" placeholder="e.g. Jude Bellingham"
                    value={form.selected_name}
                    onChange={e => set('selected_name', e.target.value)}/>
                  <small style={{ fontSize:'0.7rem', color:'var(--text-3)' }}>
                    Use the Transfermarkt name for best accuracy.
                  </small>
                </div>

                <div className="grid-2">
                  <div className="input-group">
                    <label className="field-label">Current Club</label>
                    <input className="input" placeholder="Real Madrid"
                      value={form.current_club}
                      onChange={e => set('current_club', e.target.value)}/>
                  </div>
                  <div className="input-group">
                    <label className="field-label">Buying Club</label>
                    <input className="input" placeholder="Arsenal"
                      value={form.interested_club}
                      onChange={e => set('interested_club', e.target.value)}/>
                  </div>
                </div>
              </div>
            </div>

            <div className="glass-flat" style={{ padding:24 }}>
              <h3 style={{ marginBottom:20 }}>Financial Parameters</h3>
              <div style={{ display:'flex', flexDirection:'column', gap:18 }}>

                {/* Contract Years */}
                <div className="input-group">
                  <label className="field-label">
                    Contract Years Remaining
                    <span className="range-val" style={{ float:'right' }}>{form.contract_years}yr</span>
                  </label>
                  <input type="range" min={0.5} max={7} step={0.5}
                    value={form.contract_years}
                    onChange={e => set('contract_years', parseFloat(e.target.value))}/>
                  <div className="range-row"><span>0.5yr</span><span>7yr</span></div>
                </div>

                {/* Age */}
                <div className="input-group">
                  <label className="field-label">
                    Age
                    <span className="range-val" style={{ float:'right' }}>{form.age}</span>
                  </label>
                  <input type="range" min={16} max={40} step={1}
                    value={form.age}
                    onChange={e => set('age', parseInt(e.target.value))}/>
                  <div className="range-row"><span>16</span><span>40</span></div>
                </div>

                {/* Injury days */}
                <div className="input-group">
                  <label className="field-label">Injury Days (last 24m)</label>
                  <input type="number" className="input" min={0} max={730}
                    value={form.injuries_24m}
                    onChange={e => set('injuries_24m', parseInt(e.target.value)||0)}/>
                </div>

                {/* Market value */}
                <div className="input-group">
                  <label className="field-label">Current Market Value (£m)</label>
                  <input type="number" className="input" min={0.1} step={0.5}
                    value={form.market_value_estimation}
                    onChange={e => set('market_value_estimation', parseFloat(e.target.value)||0)}/>
                </div>

                {/* Asking price */}
                <div className="input-group">
                  <label className="field-label">Selling Club Asking Price (£m)</label>
                  <input type="number" className="input" min={0.1} step={0.5}
                    value={form.asking_price}
                    onChange={e => set('asking_price', parseFloat(e.target.value)||0)}/>
                </div>
              </div>
            </div>

            <button className="btn btn-primary" style={{ width:'100%', justifyContent:'center', padding:14 }}
              onClick={handleSubmit} disabled={loading}>
              {loading
                ? <><ButtonPulse /> Fetching live intel… (15–30s)</>
                : '⚡ Calculate Hard Cap'}
            </button>

            {error && <div className="alert alert-danger">{error}</div>}
          </div>

          {/* ── Right: Results ────────────────────────────────────────────── */}
          <div>
            {!result && !loading && (
              <div className="glass" style={{ padding:48, textAlign:'center', color:'var(--text-3)' }}>
                <div style={{ fontSize:'3rem', marginBottom:16 }}>📊</div>
                <p>Results will appear here after evaluation.</p>
              </div>
            )}

            {loading && (
              <div className="glass" style={{ padding:48, textAlign:'center' }}>
                <AILoader />
                <p style={{ color: 'var(--text-1)', fontWeight: 500 }}>Running ML inference + scraping live market signals…</p>
                <p style={{ fontSize:'0.8rem', color:'var(--text-3)', marginTop:8 }}>
                  Live DDGS intel can take 15–30 seconds first time.
                </p>
              </div>
            )}

            {result && L && (
              <motion.div 
                initial={{ opacity: 0, y: 20 }}
                animate={{ opacity: 1, y: 0 }}
                transition={{ duration: 0.5 }}
                className="animate-in" 
                style={{ display:'flex', flexDirection:'column', gap:18 }}
              >

                {/* Verdict alert */}
                <div style={{ display: 'flex', gap: '12px', alignItems: 'stretch' }}>
                  <div className={`alert ${form.asking_price > L.hard_cap ? 'alert-danger' : 'alert-success'}`} style={{ flex: 1, margin: 0 }}>
                    {form.asking_price > L.hard_cap
                      ? `⚠️ OVERPAY RISK — Asking price £${form.asking_price}m exceeds our Fair Value ceiling of £${L.hard_cap.toFixed(1)}m by £${(form.asking_price - L.hard_cap).toFixed(1)}m.`
                      : `✅ FAIR DEAL — Asking price £${form.asking_price}m is within the £${L.hard_cap.toFixed(1)}m Fair Value. Proceed with confidence.`}
                  </div>
                  <div style={{ display: 'flex', flexDirection: 'column', gap: 4 }}>
                    <button onClick={handleDownloadPdf} className="btn btn-secondary" style={{ padding: '0 24px' }} title="Download Professional PDF Report">
                      <Download size={20} />
                      Download PDF Report
                    </button>
                    <span style={{ fontSize: '0.68rem', color: 'var(--text-2)', textAlign: 'center', lineHeight: 1.4 }}>
                      💡 In the print dialog, set <strong style={{ color: 'var(--text-1)' }}>Destination → Save as PDF</strong>
                    </span>
                  </div>
                </div>

                {/* Gauge + Ledger */}
                <div style={{ display:'grid', gridTemplateColumns:'1fr 1fr', gap:18 }}>
                  <div className="glass" style={{ padding:20, display:'flex', alignItems:'center', justifyContent:'center' }}>
                    <Gauge asking={form.asking_price} hardCap={L.hard_cap}/>
                  </div>

                  <div className="glass" style={{ padding:24 }}>
                    <h3 style={{ marginBottom:20 }}>XAI Valuation Ledger</h3>
                    <div style={{ display:'flex', flexDirection:'column', gap:16 }}>
                      <div>
                        <div className="metric-label">Intrinsic Performance Value</div>
                        <div className="metric-value" style={{ color:'var(--profit-color)' }}>£{L.intrinsic_performance_value.toFixed(1)}m</div>
                        <span className="badge badge-green" style={{ marginTop:4 }}>{L.category}</span>
                      </div>
                      <div className="divider" style={{ margin:'8px 0' }}/>
                      <div>
                        <div className="metric-label">Age &amp; Contract Impact &mdash; {L.depreciation > 0 ? '📉 Depreciation' : '📈 Appreciation'}</div>
                        <div className="metric-value" style={{ color: L.depreciation > 0 ? 'var(--loss-color)' : 'var(--profit-color)' }}>
                          {L.depreciation > 0 ? '-' : '+'}£{Math.abs(L.depreciation).toFixed(1)}m
                        </div>
                        <span className="badge badge-blue" style={{ marginTop:4 }}>SHAP Calculated</span>
                      </div>
                      <div className="divider" style={{ margin:'8px 0' }}/>
                      <div>
                        <div className="metric-label">ML Baseline</div>
                        <div className="metric-value">£{L.baseline_value.toFixed(1)}m</div>
                      </div>
                      <div>
                        <div className="metric-label">NLP Multiplier</div>
                        <div className="metric-value" style={{ color: L.external_multiplier > 1 ? 'var(--profit-color)' : 'var(--loss-color)' }}>
                          ×{L.external_multiplier.toFixed(3)}
                        </div>
                      </div>
                      <div style={{ padding:'12px 14px', background:'rgba(34,197,94,0.15)', borderRadius:10, border:'1px solid rgba(0,232,122,0.2)' }}>
                        <div className="metric-label">🎯 Fair Value Ceiling</div>
                        <div style={{ fontSize:'2.2rem', fontWeight:900, color:'var(--profit-color)', letterSpacing:'-0.03em' }}>
                          £{L.hard_cap.toFixed(1)}m
                        </div>
                      </div>
                    </div>
                  </div>
                </div>

                {/* SHAP Chart */}
                <div className="glass" style={{ padding:24 }}>
                  <div style={{ marginBottom:14 }}>
                    <h3>SHAP Deep Dive — Top 10 Valuation Drivers</h3>
                    <p style={{ fontSize:'0.82rem', marginTop:4 }}>
                      Green = value driver. Red = value drag. Measured in log-price space.
                    </p>
                  </div>
                  <ShapChart data={result.shap_data}/>
                </div>

                {/* NLP Results */}
                <div className="glass" style={{ padding:24 }}>
                  <div style={{ display:'flex', justifyContent:'space-between', alignItems:'center', marginBottom:18 }}>
                    <h3>Live Market Intelligence</h3>
                    {result.nlp_cached && <span className="badge badge-blue">Cached</span>}
                  </div>
                  <div style={{ display:'flex', flexDirection:'column', gap:14 }}>
                    <SentimentScore label="Injury / Availability"    icon="🏥" value={result.nlp_results.durability} found={result.nlp_found}/>
                    <SentimentScore label="Recent Form & Impact"     icon="📈" value={result.nlp_results.recency} found={result.nlp_found}/>
                    <SentimentScore label="Transfer Speculation"     icon="🗞️" value={result.nlp_results.agent} found={result.nlp_found}/>
                  </div>
                  <div style={{ marginTop:16 }}>
                    <button className="btn btn-ghost" style={{ fontSize:'0.78rem', padding:'6px 14px' }}
                      onClick={() => setShowLog(!showLog)}>
                      {showLog ? '▲ Hide' : '▼ Show'} Recon Log ({result.logs.length} entries)
                    </button>
                    {showLog && (
                      <div style={{ marginTop:12, background:'var(--bg-elevated-2)', borderRadius:8, padding:'12px 14px' }}>
                        {result.logs.map((l, i) => (
                          <div key={i} style={{ fontSize:'0.75rem', color:'var(--text-2)', padding:'3px 0', borderBottom:'1px solid var(--glass-border)' }}>{l}</div>
                        ))}
                      </div>
                    )}
                  </div>
                </div>
              </motion.div>
            )}
          </div>
        </div>

        {/* Definition of Terms Section */}
        <DefinitionOfTerms />
      </div>
      </div>

      {/* Hidden Report Template for PDF Generation */}
      {result && <ReportTemplate ref={reportRef} form={form} result={result} />}
    </div>
  )
}